1. Technical Field
The present invention relates to optical imaging devices and, particularly, to an optical lens assembly and a lens module having the same.
2. Description of Related Art
Currently, along with the development of electronic devices with multiple functions, image pick-up apparatuses have become widely used in a variety of consumer electronic devices, such as notebook computers, personal digital assistants (PDAs), cellular telephones, etc. In the meantime, demand for improving image quality is increasing, which is essentially dependent on the quality of a lens module of the image pick-up apparatus. That is, a lens module with high image quality is desired.
Referring to FIG. 5, an optical lens assembly 20 includes two lenses 24, 26. The lens 24 and lens 26 each has a central round portion and a peripheral portion. The peripheral portion of the lens 24 includes a protuberance 242, and the peripheral portion of the lens 26 includes a protuberance 262 coupled with the protuberance 242. The protuberance 242 has a surface 244 and the protuberance 262 has a surface 264. The two surfaces 244, 264 are both incline planes and have the same gradient. When assembling the two lenses 24 and 26, the surfaces 244 and 264 contact each other to engage the lens 24 to the lens 26. However, this combination requires the manufacturing tolerance of the incline plane to be very precise. If the combination is out of tolerance, the inside depth of the lens 26 to lens 24 will be different. This will make the distance between the two lenses 24 and 26 fail to meet specification. The location of contact between the two lenses 24, 26 will be unstable and may cause the lens 26 to become skewed. Furthermore, the axis of the lenses 24 and 26 will not be coincident. Thus, a lens module having the optical lens assembly 20 above may provide distorted images.
Therefore, a new optical lens assembly is desired to overcome the above mentioned problems.